Question for folks who have worked with composites: I'd like to find a "greener" type of foam to use building CarBEN EV5. I was planning on Dow XPS but I found out it is just about the worst in terms of input energy so it has a very big "carbon footprint".
It needs to be fairly rigid, machinable, and I'm going to use 1" thick x 2' x 8' square edged sheets (not tongue & groove). If it is biodegradable then that is good as long as it is not water soluble.
If I cannot find something better, then I will use XPS (because I can't let perfection be the enemy of the good!) and the best / only place I have found it for sale is here at a place in Texas -- which seems like along ways to have it shipped to New England!):
FRP Shop - DOW Brand Extruded Styrofoam Insulation